The processing of cants generally do not allow for efficient production of dimension lumber, especially when the cants have natural inherent irregularities, such as curvature and knots. A cant is conventionally defined as a log having at least two flat parallel faces. Typically, a processed cant produces a plurality of centre cant boards having flat parallel faces (i.e. useable dimension lumber) and a plurality of wane edge boards having non-flat faces from the curved surfaces of the cant. Such wane edge boards may be further processed or chipped to remove the curved surfaces in order to transform such boards into dimension lumber. However, such processes increase production costs and unnecessarily compromise recovery.
When processing a cant, typically, an upstream scanner and optimizer are used to determine the width and number of centre cant boards that can be processed from the cant. The scanner and optimizer also determine the size and width of any wane edge boards that can be milled from the curved sides of the cant and processed into dimension lumber. The methods and devices currently available in the art to profile and process wane edge boards into usable dimension lumber negatively affect recovery. Recovery, which is the most important factor in the lumber industry, refers to the amount of board feet recovered from cutting a cant into dimension lumber.
The existing methods and devices for processing wane edge boards are limited only to profiling the wane edge boards relative to the width of the centre cant boards in an orientation parallel with the direction of flow of the cant. For example, the rotational axes of the upper pair and lower pair of profiling heads available in the art are generally fixed at right angles to the direction of flow of the cant, thereby producing profiled wane edge boards without regard to the characteristics peculiar to the cant being processed. Such methods and devices for profiling wane edge boards fail to adapt to and accommodate any natural inherent irregularities of cants which can be accomplished by following the natural longitudinal centreline of the cant. For example, if the cant has a curvature in the horizontal plane, profiling heads which are generally fixed at right angles will not be able to maintain a path parallel to the longitudinal centreline of the cant, causing the profiled wane edge boards to be shortened relative to the maximum cant length. This limitation does not permit maximum recovery of the cant because the profiler produces profiled wane edge boards that fail to utilize the full length of the cant. The wane edge boards may be reduced in width or size to accommodate the deficiencies in the cant. However, this results in a reduction of lumber recovery volume and value as well.
Therefore, it is desirable to effectively process cants into useable dimension lumber by producing the maximum number of center cant boards and processing the remaining curved sides of the cant in an economical manner to produce the maximum number of profiled wane edge boards.